Devices which generate or rely upon beams, i.e. streams of particles or energy, typically incorporate elements which are used to focus, guide, or direct the beam within the device. In most cases, these elements must be properly situated and precisely aligned so as to insure the beam generation devices operate properly and at maximum efficiency. For example, oscillator-based Free Electron Lasers (FEL) require highly aligned (sub 10 μrad) optical cavity mirrors in order to insure FEL startup and for maintenance of subsequent lasing.
One of the methods currently used to align FEL mirrors is to provide an alignment laser that is coaxial to the ideal FEL path. An alignment mirror is then inserted via pneumatic air cylinder, step motor, or any such means, into position in the FEL mechanism. The alignment laser is reflected off the mirror in order to accomplish alignment. However, in order to satisfactory align the FEL on a consistent basis, the inserted alignment tools, whatever they may be, must be accurately located in exactly the same position with respect to the surrounding structure(s) for each respective insertion.
Unfortunately, conventional prior art insertion devices simply do not have the accuracy or the repeatability required to properly align the insertion target time after time. Conventional insertion devices commonly use the mechanical stops of a pneumatic cylinder and a non-rotating shaft for positioning the target. Devices that are inserted pneumatically are often positioned by the stroke of the cylinder. The difficulty is that the positioning of these devices relies on the mechanical tolerances of the equipment which does not allow for a high degree of reproducibility. In addition, under certain circumstances, such conventional devices may insert differently, i.e., in different positions, depending on the amount of air pressure applied. Finally, the prior art methods generally do not allow for any movement or adjustment of the target position once it has been inserted into a system under vacuum.
It is therefore desirable to have an insertion device and method which offers both accuracy and repeatability in vacuum and non-vacuum applications. The instant invention provides a solution to the foregoing need.